Built at a cost of more than £1.2 billion the plant, on the coast of the Irish Sea in northern England, ran into trouble from the second it opened in 2001. Its owners boasted that it would produce 120 tonnes of MOX fuel a year for nuclear reactors around the world and make £200 million in profits.

The owners of SMP made a fatal mistake in their business decision to manufacture MOX: it’s not conventional nuclear fuel and so hardly any operators of nuclear reactors use the stuff. Less than 10% of the world’s reactors can use MOX. It accounts for just 2% of the nuclear fuel used worldwide.

There are a lot of myths about the benefits of MOX fuel. That it will use up stockpiles of plutonium (it actually increases plutonium levels), that it’s cheaper to produce (it’s not), that recycling nuclear waste into MOX is a good thing (it isn’t – producing MOX actually creates more nuclear waste).

Producing MOX is a long and complicated process involving the blending of plutonium and uranium. It’s unstable to use resulting in higher safety risks and lower performance as a fuel. Though one of the arguments for using MOX is to reduce global plutonium stockpiles none of the reactors using it burn up the plutonium effectively creating highly dangerous waste.

The economic benefits of using MOX are dubious to say the least. Handling plutonium and manufacturing MOX fuel are very expensive because of the high levels of radioactivity involved. Transport costs are also huge because of the extra safety and security required. Armed transport ships are needed.

It is easier to extract the plutonium in MOX than in conventional nuclear fuel making it even more dangerous were it to fall into the wrong hands. All in all, burning MOX fuel is a waste of time and money, and creates major security and nuclear proliferation risks.

And so, in the end, the Sellafield MOX Plant found itself with just one customer: the Japanese nuclear industry. On March 11, the catastrophic tsunami and the Fukushima disaster closed nuclear reactors and prompted Japan to begin reconsidering its energy policy. The Sellafield MOX Plant’s fate was sealed.

This small step in the right direction is another vindication of all we’ve said and done in long years of campaigning. It’s also a condemnation of the nuclear industry: dangerous, expensive, highly flawed business practices and unable to support itself without bailouts from the taxpayer. The closure of the Sellafield MOX Plant is another sign that it’s time is over.